1. Field
The present disclosure relates generally to manufacturing and, in particular, to assembling parts to form structures. Still more particularly, the present disclosure relates to a method and apparatus for aligning parts using holes.
2. Background
In manufacturing aircraft, parts may be assembled to form the different structures for the aircraft. The assembly of parts may include, for example, without limitation, attaching skin panels to spars, ribs, stringers, and/or other structural components.
In attaching parts to each other, holes may be present in the parts for installing fasteners to attach the parts to each other. Further, holes also may be present to provide alignment of parts to each other in an assembly.
For example, without limitation, when multiple part holes are present in each part in assembly, these holes may be used to align the parts to each other. This type of alignment also may be referred to as self locating. This alignment may align a first part with a second part. In each part, one hole in the first part may be aligned with one hole in the second part.
These holes may be referred to as the primary holes. The other hole in the first part may be aligned with the other hole in the second part. These holes may be used to provide a desired orientation of the first part with respect to the second part. These holes may be referred to as secondary holes. The secondary holes may provide alignment to an identified location in the direction that stops rotation about the primary holes.
In manufacturing holes in parts, variances may be present with respect to various parameters for holes. These variances may include, for example, without limitation, hole size, hole orientation, hole location, and/or other types of parameters with respect to holes. When using holes to establish relative locations of parts to each other, variations in hole locations on each of the objects may prevent the holes from perfectly aligning with each other.
For example, when assembling parts, alignment of the parts using the holes may be performed by passing a pin through a primary hole in all of the parts. The insertion of this pin through the primary holes may establish a common axis or origin for the parts. Another pin may be inserted through the secondary holes. This second pin may prevent rotation around the common axis of the primary holes. The second pin may provide alignment of the different parts to each other about the common axis. The second pin also may be referred to as a locating pin.
Variation in the locations of the centers of the holes may result in the secondary holes not being perfectly aligned when positioning parts with respect to each other. With this situation, the locating pin in the secondary holes may need to have a smaller diameter than the diameters of the holes to be able to insert the locating pin into the secondary holes. This smaller sized locating pin may not locate the secondary holes in the desired direction with sufficient accuracy to stop rotation about the axis of the primary holes.
As a result, the different parts may potentially rotate relative to each other. This rotation may be an amount that is as much as the clearance between the hole sizes and the size of the locating pin. This potential movement may result in a difference in the desired location between the parts in the assembly and the actual location of the parts.
Therefore, it would be advantageous to have a method and apparatus that takes into account one or more of the issues discussed above, as well as possibly other issues.